Various opinions and information are exchanged in social media, and more than 100 million users post billions of comments. A technology of detecting a power user from the users was conventionally developed and has been serviced.
However, the conventional technology simply ranks total users or recommends a user in a particular category, but does not rank power users related to each of the all keywords to provide them. When a social web is searched through a keyword, only a document including the corresponding keyword, a user matched with the corresponding keyword, or a particular domain (category) is searched.
When a user is recommended, it is not shown which article is posted in a corresponding field by the recommended user and which article is influential in connection with an input keyword.